In a ship for transporting cargos such as containers, cargos are loaded not only in a hold below a deck but also on the deck. In a container ship for transporting containers, since cargos are accommodated in the containers, rain water does not enter the cargos in the containers even if the ship is caught in the rain during transportation or a cargo handling operation at a quay. On the other hand, a cargo ship for transporting cargos which need to be prevented from being wetted is, as described in Japanese Published Examined Application No. S47-13943, provided with a ceiling wall above a deck and includes a lower hold below the deck and an upper hold on the deck.
In order to increase the number of containers loaded on the container ship, a container ship described in Microfilm of Japanese Utility-Model Application Laid-Open Publication No. S61-27785 is provided with a retaining frame for containers on a shell of a hull above a draft line, and a container ship described in Microfilm of Japanese Utility-Model Application Laid-Open Publication No. S59-111792 is provided with a pendent member which extends outside a hull and is retractable on a deck.
On the other hand, an internal-combustion engine is generally used as a power source for driving a ship such as container ship and cargo ship, and a power generator is installed in a hull in order to supply power to electric equipments used in the ship. In a ship described in Japanese Patent Application Laid-Open Publication No. 2002-315195, a solar cell generates electric power to be supplied to electric equipments used in the ship. A solar boat described in Japanese Patent Application Laid-Open Publication No. H05-221381 is provided with a collapsible solar cell to generate energy for driving the boat.
A wing sail for using wind energy as a power source for driving a ship, as described in Japanese Patent Application Laid-Open Publication No. H05-139378, has a mast whose length is adjustable. Elongating or contracting the mast raises or reefs a sheet material as a sail.